1. Field of the Invention
The present invention relates to cup assemblies. More particularly, the present invention relates to a spill-proof cup assembly, and, in particular, a spill-proof cup assembly with a spill and shake-out inhibiting element.
2. Description of the Related Art
Cup assemblies designed to reduce or eliminate leakage or spillage are known. Such cup assemblies often employ valves or flow control elements that attempt to prevent unwanted dispensing of fluid held within the cup. Typically, such cup assemblies require hard or increased suction to be applied to the valve or flow control element for the fluid to pass through to the user, which is often due to the use of a blockage or obstruction disposed in the flow path or passageway.
An example of such a cup assembly and valve or flow control mechanism is disclosed in U.S. Pat. No. 6,422,415 to Manganiello. The Manganiello device includes a cup having an open end and a cap adapted to seal the open end. The cap has a drinking spout and a mating surface, with the mating surface being in fluid communication with the spout. The device also has a valving element that has a stack. The stack is sized and configured to engage the mating surface and thereby place the stack in fluid communication with the spout. The stack has a top portion with a concave valve face in the top portion that curves inwardly towards the stack.
An alternative type of flow control element is disclosed in U.S. Pat. No. 4,915,250 to Hayes. The Hayes device includes a container and a lid. The lid has a tubular chamber formed in the lid. The tubular chamber is a single circular or helical loop that is disposed along an outer area of the lid.
In operation, when the Hayes container is tilted between an upright vertical position and a horizontal position, i.e., rotation of up to 90°, any fluid that seeks to exit the container through the tubular chamber would be required to flow through a path along the circumference of the lid. The circumferential path would require the fluid to flow above the level of the fluid in the container, which it may not be able to do. Thus, the Hayes device intends that the fluid be prevented from exiting through the tubular chamber because the fluid cannot rise above the level of the fluid in the container. As an example, when the Hayes container is tilted or rotated to the horizontal, i.e., rotated 90°, the fluid in the tubular chamber would be required to flow up to the highest point of the lid (along the circumference), which we will call the apex of the tubular chamber. The fluid in the container is below the apex or highest point of the lid and thus fluid flow above the level of fluid in the container, past the apex of the tubular chamber, is intended to be prevented.
However, the Hayes device suffers from the drawback of leakage or spillage when the container is tilted past the horizontal, i.e., when the cup is turned between 90° and 270°. In such an orientation, which we will call upside-down or inverted for simplicity, the fluid in the container will cover the bottom side of the lid if there is enough fluid in the container. At a 180° orientation, i.e., completely upside-down or inverted, the fluid in the container is clearly covering the entire bottom side of the lid. With the fluid covering the bottom side of the lid, the path provided by the tubular chamber no longer requires any exiting fluid to flow above the level of liquid inside the container. At such an orientation of the container, i.e., upside-down or inverted, fluid can freely flow through the tubular chamber under the force of gravity and will spill or leak out of the container.
Additionally, the Hayes device can suffer from the drawback of spillage when the container is shaken. When being shaken, portions of the fluid in the tubular chamber near the apex of the tubular chamber can move past the apex due to the shaking motion. This portion of the fluid will then flow through the remainder of the tubular chamber and out of the container.
Many of the contemporary spill-proof cup assemblies suffer from the drawback of failing to eliminate significant or continuous spillage or shake-out of the fluid inside of the cup. Moreover, the contemporary devices do not facilitate drinking because increased suction is necessary to allow flow due to the use of a blockage structure in the flow path. The contemporary devices also do not facilitate cleaning of the flow control elements because they are difficult to access and have a small size that makes thoroughly cleaning difficult.